Display device and electronic device having same

ABSTRACT

Disclosed in various embodiments of the present invention are a display device and an electronic device having same, the display device comprising: a display element having at least one portion which can be changed into a curved shape; and a flexible window member stacked onto the display element, wherein the thickness of a portion of the window member is less than that of the other portions. The display device and the electronic device having same may vary according to embodiments.

TECHNICAL FIELD

The present disclosure relates to an electronic device, andparticularly, to a flexible display device and an electronic deviceincluding the same.

BACKGROUND ART

An electronic device is a device that performs a specific functionaccording to a program provided therein, such as an electronicscheduler, a portable multimedia reproducer, a mobile communicationterminal, a tablet PC, an image/sound device, a desktop/laptop PC, or avehicular navigation system, as well as a home appliance. For example,such an electronic device may output information stored therein as soundor an image. As the degree of integration of such an electronic devicehas increased, and super-high speed and large-capacity wirelesscommunication has become popular, various functions have recently beenprovided together in a single mobile communication terminal. Forexample, various functions, such as an entertainment function (e.g., agame function), a multimedia function (e.g., a music/video reproductionfunction), a communication and security function for mobile banking, aschedule management function, and an e-wallet function, are integratedin a single electronic device, in addition to a communication function.

Electronic devices are capable of outputting information, such as animage, text, and a video image by including a display device. Displaydevice have been developed from a vacuum tube type to a flat plate type,and it has become possible to provide a larger screen as the volumes ofhousehold appliances, such as televisions, have been drasticallyreduced. Further, it has also become possible to provide high-qualityimage information through a miniaturized electronic device, such as amobile communication terminal.

An electronic device, such as a mobile communication terminal, may beconfigured to be foldable so as to ensure portability. When a flexibledisplay device is mounted on a foldable electronic device, theportability of the electronic device can be maintained or improved whileproviding a larger screen in an expanded state.

Such a display device may include a display element that outputs ascreen and a window member that protects the display element. The windowmember may have sufficient strength to protect the display element fromthe external environment and sufficient transparency to transmit thescreen output from the display element therethrough. Further, in orderto prevent deterioration of image quality due to scratches or the likeof the window member, the surface hardness of the window member may bestrengthened by forming a hard coating layer on the surface of thewindow member using a ceramic, acryl, or the like.

DETAILED DESCRIPTION OF THE INVENTION Technical Problem

However, in a flexible display device, the window member also hasflexibility, which may make it difficult to secure sufficient strengthto protect the display device. For example, when a touch-screen functionis incorporated in the display device, the user frequently touches thesurface of the window member, and in the flexible display device,external pressure (e.g., contact pressure applied by the user) may betransferred to the display device.

It may be possible to prevent the contact pressure applied by the userfrom being transferred to the display element by, for example,increasing the thickness of the window member so that the mechanicalstrength of the window member can be increased. However, since theflexibility of the window member is deteriorated as the mechanicalstrength of the window member is increased, there is a limit in theextent to which the thickness of the window member in the flexibledisplay device can be increased.

Therefore, various embodiments of the present disclosure provide aflexible display device which is capable of preventing external pressurefrom being transferred to a display element while ensuring theflexibility thereof, and provide an electronic device having theflexible display device.

In addition, various embodiments of the present disclosure provide adisplay device capable of outputting a screen of good quality whileensuring the flexibility and strength thereof, and provide an electronicdevice having the display device.

Technical Solution

Disclosed in various embodiments of the present disclosure are a displaydevice and an electronic device having the same, the display deviceincluding: a display element, at least a portion of which is deformablein a curved shape; and a flexible window member stacked on the displayelement. A portion of the window member is formed to have a thicknesssmaller than the thickness of a remaining portion of the window member.

The window member may include a stepped portion or a curved portion onat least one face thereof such that a portion, in which the steppedportion or the curved portion is formed, may be formed to be thinnerthan a remaining portion.

In some embodiments, the display device may include:

a display element, at least a portion of which is deformable in a curvedshape;

a flexible window member stacked on the display element; and

a first film member laminated on at least one face of the window member.

When the window member is mounted on an electronic device, a portionhaving a reduced thickness may be disposed to correspond to a portion,which is deformed into a curved shape according to, for example, anopening/closing operation of the electronic device. Through thisarrangement, the deformation of the window member according to theopening/closing operation of the electronic device can be smoothlyperformed.

Advantageous Effects

The display device according to various embodiments of the presentdisclosure and the electronic device are able to secure flexibility byimplementing a portion (e.g., a portion to be deformed into a curvedshape) so as to have a thickness smaller than the other portions inconfiguring the window member that protects the display element. Inconfiguring the display device described above, it is possible toprevent external pressure from being transferred to the display elementby securing a sufficient thickness in a portion of the window member,other than the portion that is to be deformed into the curved shape.Further, in a display device according to various embodiments of thepresent disclosure and an electronic device having the display device,when a variation in the quality of an image, which has been transmittedthrough the window member due to the difference in thickness of thewindow member occurs, it is possible to output a screen of good qualityby forming a reinforcing layer so as to compensate for the deviation inimage quality.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating an electronic device includinga display device according to various embodiments of the presentdisclosure;

FIG. 2 is a cross-sectional view illustrating the configuration of theelectronic device including the display device according to variousembodiments of the present disclosure;

FIG. 3 is a cross-sectional view illustrating the configuration of aconventional flexible display device in the state in which externalpressure is applied thereto;

FIG. 4 is a cross-sectional view illustrating a configuration of adisplay device according to one of various embodiments of the presentdisclosure;

FIG. 5 is a view illustrating a window member of a display deviceaccording to one of various embodiments of the present disclosure;

FIG. 6 is a view illustrating various modifications of the window memberof the display device according to one of various embodiments of thepresent disclosure;

FIG. 7 is a cross-sectional view illustrating the configuration of adisplay device according to another one of various embodiments of thepresent disclosure in order to explain the display device;

FIG. 8 is a cross-sectional view illustrating the configuration of adisplay device according to still another one of various embodiments ofthe present disclosure in order to explain the display device;

FIG. 9 illustrates views for explaining a process of manufacturing awindow member of a display device according to various embodiments ofthe present disclosure;

FIG. 10 is a perspective view illustrating a window member of a displaydevice according to various embodiments of the present disclosure;

FIG. 11 is a view for explaining compressive force or tensile forceformed in a curved portion of a window member;

FIG. 12 is a view illustrating a curved portion of a window member of adisplay device according to various embodiments of the presentdisclosure;

FIG. 13 is a block diagram illustrating an electronic device accordingto various embodiments of the present disclosure;

FIG. 14 is a cross-sectional view schematically illustrating theconfiguration of an electronic device according to one of variousembodiments of the present disclosure in a folded state;

FIG. 15 is a cross-sectional view schematically illustrating theconfiguration of an electronic device according to another one ofvarious embodiments of the present disclosure in a folded state; and

FIGS. 16 to 20 are cross-sectional views illustrating partialconfigurations of display devices according to various embodiments ofthe present disclosure, respectively.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, various embodiments of the present disclosure will bedescribed with reference to the accompanying drawings. However, itshould be understood that there is no intent to limit the presentdisclosure to the particular forms disclosed herein; rather, the presentdisclosure should be construed to cover various modifications,equivalents, and/or alternatives of embodiments of the presentdisclosure. In describing the drawings, similar reference numerals maybe used to designate similar constituent elements.

In the various embodiments of the present disclosure, the expression “Aor B”, “at least one of A or/and B”, or “one or more of A or/and B” mayinclude all possible combinations of the items listed. For example, theexpression “A or B”, “at least one of A and B”, or “at least one of A orB” refers to all of (1) including at least one A, (2) including at leastone B, or (3) including all of at least one A and at least one B.

The expression “a first”, “a second”, “the first”, or “the second” usedin various embodiments of the present disclosure may modify variouscomponents regardless of the order and/or the importance but does notlimit the corresponding components. For example, a first user device anda second user device indicate different user devices although both ofthem are user devices. For example, a first element may be termed asecond element, and similarly, a second element may be termed a firstelement without departing from the scope of the present disclosure.

It should be understood that when an element (e.g., first element) isreferred to as being (operatively or communicatively) “connected,” or“coupled,” to another element (e.g., second element), it may be directlyconnected or coupled directly to the other element or any other element(e.g., third element) may be interposer between them. In contrast, itmay be understood that when an element (e.g., first element) is referredto as being “directly connected,” or “directly coupled” to anotherelement (second element), there are no element (e.g., third element)interposed between them.

The expression “configured to” used in the present disclosure may beexchanged with, for example, “suitable for”, “having the capacity to”,“designed to”, “adapted to”, “made to”, or “capable of” according to thesituation. The term “configured to” may not necessarily imply“specifically designed to” in hardware. Alternatively, in somesituations, the expression “device configured to” may mean that thedevice, together with other devices or components, “is able to”. Forexample, the phrase “processor adapted (or configured) to perform A, B,and C” may mean a dedicated processor (e.g., embedded processor) onlyfor performing the corresponding operations or a generic-purposeprocessor (e.g., Central Processing Unit (CPU) or Application Processor(AP)) that can perform the corresponding operations by executing one ormore software programs stored in a memory device.

In the present disclosure, the terms are used to describe specificembodiments, and are not intended to limit the present disclosure. Asused herein, the singular forms are intended to include the plural formsas well, unless the context clearly indicates otherwise. In thedescription, it should be understood that the terms “include” or “have”indicate existence of a feature, a number, a step, an operation, astructural element, parts, or a combination thereof, and do notpreviously exclude the existences or probability of addition of one ormore another features, numeral, steps, operations, structural elements,parts, or combinations thereof.

Unless defined differently, all terms used herein, which includetechnical terminologies or scientific terminologies, have the samemeaning as that understood by a person skilled in the art to which thepresent disclosure belongs. Such terms as those defined in a generallyused dictionary are to be interpreted to have the meanings equal to thecontextual meanings in the relevant field of art, and are not to beinterpreted to have ideal or excessively formal meanings unless clearlydefined in the present specification. In some cases, terms defined inthis specification may not be interpreted as excluding embodiments ofthe present disclosure.

In the present disclosure, an electronic device may be a random device,and the electronic device may be called a terminal, a portable terminal,a mobile terminal, a communication terminal, a portable communicationterminal, a portable mobile terminal, a touch screen or the like.

For example, the electronic device may be a smartphone, a portablephone, a game player, a TV, a display unit, a heads-up display unit fora vehicle, a notebook computer, a laptop computer, a tablet PersonalComputer (PC), a Personal Media Player (PMP), a Personal DigitalAssistants (PDA), and the like. The electronic device may be implementedas a portable communication terminal which has a wireless communicationfunction and a pocket size. Further, the electronic device may be aflexible device or a flexible display device.

The electronic device may communicate with an external electronicdevice, such as a server or the like, or perform an operation through aninterworking with the external electronic device. For example, theelectronic device may transmit an image photographed by a camera and/orposition information detected by a sensor unit to the server through anetwork. The network may be a mobile or cellular communication network,a Local Area Network (LAN), a Wireless Local Area Network (WLAN), a WideArea Network (WAN), an Internet, a Small Area Network (SAN) or the like,but is not limited thereto.

FIG. 1 is a perspective view illustrating an electronic device 10 thatincludes a display device 15 according to various embodiments of thepresent disclosure. FIG. 2 is a cross-sectional view illustrating theelectronic device 10 that includes the display device 15 according tovarious embodiments of the present disclosure.

Referring to FIGS. 1 and 2, an electronic device 10 including thedisplay device 15 according to various embodiments of the presentdisclosure may be a folder-type electronic device that includes a pairof housings 11 and 13, which are pivotably coupled to each other by ahinge device 17. For example, the housings 11 and 13 may be folded orunfolded with respect to each other by rotating about a hinge axis Hprovided by the hinge device 17. The display device 15 is a flexibledisplay device, which is at least partially bendable. Of the housings 11and 13, a portion of the display device 15 is arranged in and mounted ona first housing 11, and another portion of the display device 15 isarranged in and mounted on the second housing 13 of the housings 11 and13. The display device 15 may be integrated with a touch panel so as tobe used as an input device. For example, a virtual keypad may beimplemented in a region of the display device 15 so that the user mayconveniently input desired information even if the electronic device 10does not have a physical keypad.

In the state in which the first and second housings 11 and 13 arefolded, the display device 15 is deformed into a curved shape having apredetermined curvature at a position adjacent to the hinge device 17 soas to be bent together with the first and second housings 11 and 13.When the first and second housings 11 and 13 are rotated and unfoldedwith respect to each other, the display device 15 may also be unfoldedin a flat plate shape so as to output a screen. Therefore, the user mayeasily carry the electronic device 10 by folding the first and secondhousings 11 and 13, and when using the electronic device 10, the firstand second housings 11 and 13 may be extended, so that it is possible toconfirm various pieces of information, (e.g., an image, a text, or avideo image) output through the large screen. In addition, as describedabove, by implementing the virtual keypad through the display device 15as required, the user may store or output desired information and thelike through the electronic device 10.

As mentioned above, the display device 15 may be at least partiallydeformed in a curved shape. For example, when the first and secondhousings 11 and 13 are folded to face each other, the display device 15may be curved in a portion adjacent to the hinge device 17. As will bedescribed later, the display device 15 may include a window member, andthe thickness of the window member may be formed smaller in a portionthat is to be deformed in a curved shape than in the other portions.

FIG. 3 is a cross-sectional view illustrating the configuration of aconventional flexible display device in the state in which externalpressure is applied thereto.

Referring to FIG. 3, a conventional flexible display device 15 may havea sufficiently thin thickness to be deformed in a curved shape.Therefore, the display element 15 a and the window member 15 c forprotecting the display element 15 a may have a sufficiently thinthickness. In a conventional flexible display device, the window member15 c may have a surface hardness that is resistant to damage, such asscratches, by including a cured coating layer. However, when externalpressure is applied in the state in which the window member 15 c islaminated and bonded to the display element 15 a by an Optically ClearAdhesive (OCA) 15 b, the window member 15 c may be deformed in a portion15 d to which pressure is applied. The deformation of the window member15 c transfers the externally applied pressure to the display element 15a and may thus cause distortion of the screen in the portion 15 e wherethe pressure is applied on the display element 15 a, or damage to thedisplay element 15 a.

The mechanical strength of the window member 15 c can be improved byincreasing the thickness of the window member 15 c in order to preventthe distortion of the screen or damage to the display element. However,as described above, this may also decrease the flexibility of theflexible display device.

Therefore, according to various embodiments of the present disclosure,the display device may include a window member having a structure thatis capable of securing flexibility while preventing the distortion of ascreen or damage to the display element due to external pressure or thelike. According to various embodiments of the present disclosure, thewindow member of the display device may be formed to be thinner in aportion (e.g., a portion where flexibility is required) than the otherportions, thereby ensuring flexibility. In the display device accordingto various embodiments of the present disclosure, since the thickness ofthe window member can be sufficiently secured in the portion whereflexibility is not required, it is possible to prevent external pressurefrom being transferred to the display element.

FIG. 4 is a cross-sectional view illustrating the configuration of adisplay device 15 according to one of various embodiments of the presentdisclosure. FIG. 5 is a view illustrating a window member 153 of thedisplay device 15 according to one of various embodiments of the presentdisclosure.

Referring to FIGS. 4 and 5, according to one of various embodiments ofthe present disclosure, the display device 15 includes a curved portion159 a formed in at least a portion of the window member 153, therebyforming a thickness smaller than the other portions of the window member153, in which the curved portion 159 a is not formed. As will bedescribed below, the curved portion does not necessarily have to beformed in order to make the thickness of a portion of the window member153 smaller than the other portions. For example, a stepped portion maybe formed on one face or both faces of the window member 153 such thatthe thickness of a portion of the window member 153 may be thinner thanthe other portions. When the curved portions 159 a (or the steppedportions) are formed on both faces of the window member 153, the curvedportions 159 a (or the stepped portions) may be symmetrically arranged.

The window member 153 may be stacked on one face of the flexible displayelement 151 and may be bonded to the display element 151 by an opticaladhesive 155. The window member 153 and the optical adhesive 155 mayeach be made of a transparent material, and may transmit a screen outputfrom the display element 151. The flexibility of the window member 153may be increased at the portion where the curved portion 159 a isformed. When the display device 151 is mounted on an electronic device(e.g., the electronic device 10), a portion (e.g., a portion thinnerthan the other portions) of the window member 151 may be disposed in thevicinity of the hinge device 17 described above or in a region which isbent in a curved shape, so that the portion can be deformed in a curvedshape in an operation of opening/closing the electronic device 10.

The curved portion 159 a may be formed on one face or on each face ofthe window member 153. When the curved portion 159 a is formed on oneface of the window member 153 and the electronic device 10 is folded,the curved portion 159 a may be formed on the face, which is convexlydeformed as the window member 153 is deformed in a curved shape. Inaddition, as described above, the curved portion 159 a may be formed oneach face of the window member 153. The position or the like of thecurved portion 159 a formed on the window member 153 may be variouslyset according to the specification of the electronic device, on whichthe display device 15 is to be mounted. The curved portion 159 a mayhave a curved groove shape extending in the width direction W of thewindow member 153 and may have a shape in which the thickness of thewindow member 153 gradually increases while extending from the centerportion toward the edges of the window member 153 in the longitudinaldirection L of the window member 153.

When the display device 15 includes a touch-screen function, the curvedportion 159 a may correspond to a portion that accepts an inputoperation (e.g., a physical touch) of the user. The width of the curvedportion 159 a (e.g., the size of the curved portion 159 a in thelongitudinal direction L of the window member 153) may be smaller thanan area to be touched by the user's body. Therefore, even if the windowmember 153 is formed thin enough to be flexible in the portion in whichthe curved portion 159 a is formed, it is possible to prevent thepressure applied to the curved portion due to the user's body contact orthe like from being transferred to the display element 151.

The window member 153 may be formed by processing a transparentsynthetic resin film. In order to secure the surface hardness thereof, acured coating layer may be formed on the outer face of the syntheticresin film for forming the window member 153. The cured coating layermay be formed by coating or depositing a material, such as ceramic oracryl, on one face (e.g., the outer face) of the synthetic resin film.Processing a portion (e.g., the curved portion 159 a) of the windowmember 153 to have a thin thickness may be performed simultaneously withforming the synthetic resin film. For example, a synthetic resin filmmay be manufactured using processes, such as roller pressing, filmextrusion, stamping, and cell casting, and the shape of a roller, amold, or the like may be stamped on the above-described curved portion159 a in advance, so that the portion of the synthetic resin film can beformed thinner than the other portions simultaneously with the formationof the synthetic resin film. According to various embodiments, thesynthetic resin film for forming the window member 153 may be formed tohave a predetermined thickness, and the manufactured synthetic resinfilm may be subjected to mechanical processes (e.g., polishing, latheprocessing, laser processing, etc.) so as to form the curved surfaceportion 159 a or the like.

Depending on the size of the display device 15 or the folded shape ofthe electronic device 10, the width of the curved portion 159 a may beformed to be larger than an area to be touched by the user's body. Whenthe width of the curved portion 159 a is formed to be large, it may bedifficult to prevent the pressure applied to a portion corresponding tothe curved portion 159 a from being transferred to the display device151 by the window member 153 itself. According to various embodiments,the display device 15 may further include a reinforcing layer 157,thereby securing the mechanical strength of the portion in which thecurved portion 159 a is formed (i.e., the portion of the window member153 that is thinner than the other portions). For example, thereinforcing layer 157 may prevent a portion of the window member 153that corresponds to the curved surface portion 159 a, from beingdeformed due to a physical touch or the like.

According to various embodiments, the reinforcing layer 157 maycompensate for deviation in image quality that may occur due to thevariation in the thickness of the window member 153. That is, since thethickness of the window member 153 is not uniform, a quality differencemay occur in an image that has been transmitted through the windowmember 153 due to the difference in thickness. This image qualitydeviation may degrade the image quality of the screen output from thedisplay element 151. For example, there may be a difference between thescreen brightness of the portion where the curved portion 159 a isformed and the screen brightness of the other portions. The reinforcinglayer 157 may be formed to maintain uniform optical properties of thewindow member 153 and uniform mechanical strength of the window member153. The compensation layer 157 may be formed of a material having arefractive index similar to or the same as the refractive index of thewindow member 153.

FIG. 6 is a view illustrating various modifications of the window memberof the display device according to one of various embodiments of thepresent disclosure.

According to various embodiments of the present disclosure, a shape forreducing the thickness of a portion of the window member 153 (e.g., thecurved portion 159 a described above) may be formed on one face or eachface of the window member 153, and may be replaced by various shapes ofstepped portions 159 b. In the following detailed description, thereference numerals for the window members may be given differentlydepending on the shape of the curved portion 159 a or the steppedportion 159 b, and the term “window member” denoted by reference numeral153 may be used to mean window members each including curved portions159 a or stepped portions 159 b having different shapes.

For example, the window members indicated by reference numerals 153 aand 153 b may include a rectangular stepped portion 159 b, the windowmembers indicated by reference numerals 153 e and 153 f may include acentral flat portion and a stepped portion 159 b having inclinedportions extending toward edges in the longitudinal direction of themembers 153 e and 153 f, and the window members indicated by thereference numerals 153 g and 153 h may include stepped portions 159 b ina step shape, which gradually increase the thickness of the windowmembers 153 g and 153 h as extending from the center toward the edges inthe longitudinal direction of the window members 153 g and 153 h. Asdescribed above, the structure for making the thickness of the windowmember 153 smaller than the other portions may be formed of a curvedportion 159 a or a stepped portion 159 b, and the shapes thereof may bevariously processed.

The stepped portion 159 b may have a groove shape extending in the widthdirection W of the window member 153 similarly to the curved portion 159a. However, in the configuration of the present disclosure, theconfiguration (e.g., the stepped portion 159 b or the curved portion 159a) for making the thickness of the window member 153 smaller than theother portions does not necessarily have to extend in the widthdirection W of the window member 153. For example, when the displaydevice 15 is mounted on the electronic device 10, the direction, number,and positions of the stepped portions 159 b or the curved portions 159 aformed as described above may be appropriately set and arranged inconsideration of the structure, direction, etc. in which the electronicdevice 10 is folded.

FIG. 7 is a cross-sectional view illustrating the configuration of adisplay device 15 according to another one of various embodiments of thepresent disclosure in order to explain the display device 15. FIG. 8 isa cross-sectional view illustrating the configuration of a displaydevice 15 according to still another one of various embodiments of thepresent disclosure in order to explain the display device 15.

Referring to FIGS. 7 and 8, the reinforcing layer 157 described abovemay be formed of a transparent material, such as silicon oxide (SiOx),in the stepped portion 159 b (or the curved surface portion 159 a) onthe window member, or on the entirety of one face (or each face) of thewindow member 153, which is formed with the stepped portion 159 b (orthe curved surface portion 159 a), so as to make the portion that isformed with the stepped portion 159 b, flush with the other portions onthe one face (or each face) of the window member 153. The window member153 may be bonded to the display element 151 by an optical adhesive 155in the state in which the reinforcing layer 157 is formed. Therefore,the reinforcing layer 157 may be sealed between the window member 153and the optical adhesive 155. The reinforcing layer 157 may reinforcethe mechanical strength of the window member 153, as described above.For example, in the state in which the display device 151 is unfolded,by reinforcing the strength of a portion of the window member 153 (e.g.,the portion in which the stepped portion 159 b or the curved portion 159a is formed) having a smaller thickness in comparison with the otherportions, it is possible to prevent external pressure applied due to theuser's physical touch or the like from being transferred to the displaydevice 151. In addition, the deviation in image quality, which may occurdue to the non-uniform thickness of the window member 153, can becompensated for by forming the reinforcing layer 157.

The window member 153 of the display device described above includes thecurved portion 159 a (or the stepped portion) so that the window membercan be easily processed in a curved shape. For example, although thewindow member 153 need not be flexible, the curved portion can be easilyformed by forming the curved portion 159 a (or the stepped portion) inthe window member 153 if the window member 153 has a partially curvedsurface.

FIG. 9 illustrates views for explaining a process of manufacturing awindow member 153 of the display device (S10) according to variousembodiments of the present disclosure.

The window member 153 may be a piece of tempered glass having a flatshape and a uniform thickness before being processed into a curvedportion. A curved portion 159 a (or a stepped portion) may be formed ina certain portion of the tempered glass material in the form of a flatplate (S11). The curved portion 159 a (or the stepped portion) may beformed by pressing the tempered glass material by a roller having aprojection on the outer surface thereof, or through processes, such asetching, polishing, lathe processing, laser processing, and the like.According to various embodiments, the curved portion may be formedsimultaneously with the formation of a piece of flat tempered glassthrough a cell-casting process.

The window member 153, which is formed with the curved surface portion159 a on one face or each face thereof, may be processed into apartially curved shape from the flat shape by being bent at leastpartially through the thermoforming (S13). In the process ofthermoforming (S13), the flat window member 153 may be pressed by thepress 230 in the state of being mounted on the base 210, thereby beingdeformed to conform to the curved shape formed on the base 210. Whilebeing pressed by the press 230, heat may be applied to the flat windowmember 153 so as to facilitate deformation to the curved surface shape.

The curved portion 159 a is provided so as to form the thickness T1 ofthe portion of the window member 153 to be smaller than the thickness T2of the other portions, and when the window member 153 is processed fromthe flat shape into the shape having the curved shape, the portion inwhich the curved portion 159 a is formed can be deformed. The state inwhich the window member 153 is processed into the curved shape isillustrated in “S15”.

FIG. 10 is a perspective view illustrating a window member 153 of adisplay device according to various embodiments of the presentdisclosure. FIG. 11 is a view for explaining compressive force ortensile force formed in a curved portion of a window member. FIG. 12 isa view illustrating a curved portion of a window member 153 of a displaydevice according to various embodiments of the present disclosure.

Referring to FIGS. 10 and 11, in partially processing the window member153 from a flat shape to a curved shape, locally different forces may beapplied to the inner surface and the outer surface of the curved surfaceportion, respectively. For example, when there is no change in lengtheven after being deformed into a curved shape along the center line ofthe window member (neutral axis), compressive force may be applied tothe inner side of the center line (neutral axis), and tensile force maybe applied on the outer side thereof. When there is no change in thelength of the inner face of the window member after being deformed intoa curved shape, tensile force may act on the outer face. When there isno change in the length of the outer face of the window member afterbeing deformed into a curved shape, compressive force may act on theinner face. In this way, when the flat window member is deformed into acurved shape, deviation may occur between the force acting on the innerface and the force acting on the outer face of the deformed portion,which may lead to a molding failure of the window member. Further, asthe flat window member becomes thicker, the deviation between the forcesgenerated in the portion deformed into the curved shape may becomelarger. In order to prevent this, it is possible to process a flattempered glass material into a curved window member while heating for asufficient time in the thermoforming process.

Referring to FIG. 12, the window member 153 of the display deviceaccording to various embodiments of the present disclosure may be firstformed with the curved portion 159 a at a portion to be deformed into acurved shape before it is processed into the curved shape. For example,the portion to be deformed into the curved surface may be processed suchthat the thickness T1 thereof is made to be smaller than the thicknessT2 of the other portions. As described above, in processing the flatwindow member 153 into a curved shape, when the thickness of the windowmember 153 is thick, a deviation may increase between forces generatedin the deformed portion. The window member 153 of the display deviceaccording to various embodiments of the present disclosure may alleviatethe defective formation of the window member 153 by reducing thedeviation between the forces generated by processing the thickness ofthe portion deformed into the curved shape to be smaller than otherportions. In addition, it is possible to reduce the time required forthe thermoforming process by reducing the defects caused by thedeviation between the forces.

FIG. 13 is a block diagram illustrating an electronic device 20according to various embodiments of the present disclosure.

Referring to FIG. 13, the electronic device 20 may include, for example,all or part of the electronic device 10 illustrated in, for example,FIG. 1. The electronic device 20 may include at least one processor(e.g., Application Processor (AP)) 21, a communication module 22, asubscriber identification module 22 g, a memory 23, a sensor module 24,an input device 25, a display 26, an interface 27, an audio module 28, acamera module 29 a, a power management module 29 d, a battery 29 e, anindicator 29 b, and a motor 29 c.

The processor 21 may drive, for example, an operating system or anapplication so as to control a plurality of hardware or softwarecomponents connected thereto, and may also perform various dataprocessing and arithmetic operations. The processor 21 may beimplemented by, for example, a System-on-Chip (SoC). According to oneembodiment, the processor 21 may further include a Graphic ProcessingUnit (GPU) and/or an image signal processor. The processor 21 mayinclude at least some components (e.g., the cellular module 22 a) amongthe components illustrated in FIG. 13. The processor 21 may load acommand or data received from at least one of the other components(e.g., a non-volatile memory) in a volatile memory to process thecommand and data, and may store various data in non-volatile memory.

The communication module 22 may include, for example, a cellular module22 a, a Wi-Fi module 22 b, a Bluetooth module 22 c, a GNSS module 22 d(e.g., a GPS module, a GLONASS module, a BeiDou module, or a Galileomodule), an NFC module 22 e, and a Radio Frequency (RF) module 22 f.

The cellular module 22 a may provide, for example, a voice call, a videocall, a message service, or an internet service through, for example, acommunication network. According to one embodiment, the cellular module22 a may perform discrimination and authentication of the electronicdevice 20 within the communication network using the subscriberidentification module (e.g., a SIM card) 22 g. According to oneembodiment, the cellular module 22 a may perform at least some of thefunctions that may be provided by the processor 21. According to oneembodiment, the cellular module 22 a may include a CommunicationProcessor (CP).

Each of the Wi-Fi module 22 b, the Bluetooth module 22 c, the GNSSmodule 22 d, and the NFC module 22 e may include, for example, aprocessor to process data transmitted/received through a correspondingmodule. According to a certain embodiment, at least some (e.g., two ormore) of the cellular module 22 a, the Wi-Fi module 22 b, the Bluetoothmodule 22 c, the GNSS module 22 d, and the NFC module 22 e may beincorporated in a single Integrated Chip (IC) or an IC package.

The RF module 22 f may transmit/receive, for example, a communicationsignal (e.g., an RF signal). The RF module 22 f may include, forexample, a transceiver, a Power Amp Module (PAM), a frequency filter, aLow Noise Amplifier (LNA), or an antenna. According to anotherembodiment, at least one of the cellular module 22 a, the Wi-Fi module22 b, the Bluetooth module 22 c, the GNSS module 22 d, and the NFCmodule 22 e may transmit/receive an RF signal through one or moreseparate RF modules.

The subscriber identification module 22 g may include, for example, acard that includes a subscriber identification module and/or an embeddedSIM, and may also include intrinsic identification information (e.g., anIntegrated Circuit Card IDentifier (ICCID)) or subscriber information(e.g., an International Mobile Subscriber Identity (IMSI)).

The memory 23 may include, for example, an internal memory 23 a or anexternal memory 23 b. The internal memory 23 a may include at least oneof, for example, volatile memory (e.g., a Dynamic RAM (DRAM), a StaticRAM (SRAM), or a Synchronous DRAM (SDRAM)), and non-volatile memory(e.g., a One-Time Programmable ROM (OTPROM), a Programmable ROM (PROM),an Erasable and Programmable ROM (EPROM), an Electrically Erasable andProgrammable ROM (EEPROM), a mask ROM, a flash ROM, a flash memory(e.g., a NAND flash memory or a NOR flash memory), a hard drive, or aSolid-State Drive (SSD)).

The external memory 23 b may further include a flash drive (e.g.,Compact Flash (CF), Secure Digital (SD), Micro Secure Digital(Micro-SD), Mini Secure Digital (Mini-SD), extreme Digital (xD),Multi-Media Card (MMC), or memory stick). The external memory 23 b maybe functionally and/or physically connected to the electronic device 20through any of various interfaces.

For example, the sensor module 24 may measure a physical quantity or maysense the operating status of the electronic device 20, and may thenconvert the measured or sensed information into electric signals. Thesensor module 24 may include at least one of, for example, a gesturesensor 24 a, a gyro sensor 24 b, an atmospheric pressure sensor 24 c, amagnetic sensor 24 d, an acceleration sensor 24 e, a grip sensor 24 f, aproximity sensor 24 g, a color sensor 24 h (e.g., an RGB (Red, Green,Blue) sensor), a biometric sensor 24 i, a temperature/humidity sensor 24j, an illuminance sensor 24 k, and an Ultra-Violet (UV) sensor 24 l.Additionally, or alternatively, the sensor module 24 may include, forexample, an E-nose sensor, an ElectroMyoGraphy (EMG) sensor (notillustrated), an ElectroEncephaloGram (EEG) sensor, an ElectroCardioGram(ECG) sensor, an Infra-Red (IR) sensor, an iris sensor, and/or afingerprint sensor. The sensor module 24 may further include a controlcircuit for controlling one or more sensors incorporated therein. In acertain embodiment, the electronic device 20 may further include aprocessor configured to control the sensor module 24 as a part of theprocessor 21 or separately from the processor 21 so as to control thesensor module 24 while the processor 21 is in the sleep state.

The input device 25 may include, for example, a touch panel 25 a, a(digital) pen sensor 25 b, a key 25 c, or an ultrasonic input device 25d. As the touch panel 25 a, at least one of, for example, acapacitive-type touch panel, a resistive-type touch panel, aninfrared-type touch panel, and an ultrasonic-type panel may be used. Inaddition, the touch panel 25 a may further include a control circuit.The touch panel 25 a may further include a tactile layer so as toprovide a tactile reaction to a user.

The (digital) pen sensor 25 b may be, for example, a portion of thetouch panel or may include a separate recognition sheet. The key 25 cmay include, for example, a physical button, an optical key, or akeypad. The ultrasonic input device 25 d may sense, through a microphone(e.g., a microphone 28 d), ultrasonic waves that are generated by aninput tool so as to confirm data corresponding to the sensed ultrasonicwaves.

The display 26 may include a panel 26 a, a hologram device 26 b, or aprojector 26 c. The panel 26 a may include a configuration that is thesame as or similar to that of the above-described display device 15. Thepanel 26 a may be implemented to be flexible, transparent, or wearable.The panel 26 a may be configured as a single module with the touch panel25 a. The hologram device 26 b may show a stereoscopic image in the airusing interference of light. The projector 26 c may project light onto ascreen so as to display an image. The screen may be located, forexample, inside or outside the electronic device 20. According to oneembodiment, the display 26 may further include a control circuit tocontrol the panel 26 a, the hologram device 26 b, or the projector 26 c.

The interface 27 may include, for example, a High-Definition MultimediaInterface (HDMI) 27 a, a Universal Serial Bus (USB) 27 b, an opticalinterface 27 c, or a D-subminiature (D-sub) interface 27 d.Additionally, or alternatively, the interface 27 may include, forexample, a Mobile High-definition Link (MHL) interface, a Secure Digital(SD) card/Multi-Media Card (MMC) interface, or an Infrared DataAssociation (IrDA) standard interface.

The audio module 28 may bi-directionally convert sound and an electricsignal. The audio module 28 may process sound information input oroutput through a speaker 28 a, a receiver 28 b, an earphone 28 c, amicrophone 28 d, or the like.

The camera module 29 a is a device that is capable of photographing, forexample, a still image and a moving image. According to one embodiment,the camera module 29 a may include one or more image sensors (e.g., afront sensor or a rear sensor), a lens, an Image Signal Processor (ISP),or a flash (e.g., LED or xenon lamp).

The power management module 29 d may manage, for example, the electricpower of the electronic device 20. According to one embodiment, thepower management module 29 d may include a Power Management IntegratedCircuit (PMIC), a charger Integrated Circuit (IC), or a battery or fuelgauge. The PMIC may be configured as a wired and/or wireless chargingtype. The wireless charging type may include, for example, a magneticresonance type, a magnetic induction type, or an electromagnetic wavetype, and may further include an additional circuit for wirelesscharging (e.g., a coil loop, a resonance circuit, or a rectifier). Thebattery gauge may measure the remaining charge of the battery 29 e, anda voltage, a current, or a temperature during charging. The battery 29 emay include, for example, a rechargeable battery and/or a solar battery.

The indicator 29 b may indicate a specific status of the electronicdevice 20 or of a part thereof (e.g., the processor 21), such as abooting status, a message status, or a charged status. The motor 29 cmay convert an electric signal into a mechanical vibration, and maygenerate, for example, a vibration or a haptic effect. Although notillustrated, the electronic device 20 may include a processor (e.g., aGPU) to support a mobile TV. The processor to support a mobile TV mayprocess media data according to standards of, for example, DigitalMultimedia Broadcasting (DMB), Digital Video Broadcasting (DVB), orMediaFlo™.

Each of the above-described component elements of hardware according tothe present disclosure may be configured with one or more components,and the names of the corresponding component elements may vary based onthe type of electronic device. The electronic device according tovarious embodiments of the present disclosure may include at least oneof the aforementioned elements. Some elements may be omitted or otheradditional elements may be further included in the electronic device.Also, some of the hardware components according to various embodimentsmay be combined into one entity, which may perform functions identicalto those of the relevant components before the combination.

The term “module” as used herein may, for example, mean a unit includingone of hardware, software, and firmware or a combination of two or moreof them. The “module” may be interchangeably used with, for example, theterm “unit”, “logic”, “logical block”, “component”, or “circuit”. The“module” may be a minimum unit of an integrated component element or apart thereof. The “module” may be a minimum unit for performing one ormore functions or a part thereof. The “module” may be mechanically orelectronically implemented. For example, the “module” according to thepresent disclosure may include at least one of an Application-SpecificIntegrated Circuit (ASIC) chip, a Field-Programmable Gate Arrays (FPGA),and a programmable-logic device for performing operations which has beenknown or are to be developed hereinafter.

According to various embodiments, at least some of the devices (forexample, modules or functions thereof) or the method (for example,operations) according to the present disclosure may be implemented by acommand stored in a computer-readable storage medium in a programmingmodule form. When the command is executed by one or more processors, theone or more processors may perform a function corresponding to thecommand.

The computer readable recoding medium may include a hard disk, a floppydisk, magnetic media (e.g., a magnetic tape), optical media (e.g., aCompact Disc Read Only Memory (CD-ROM) and a Digital Versatile Disc(DVD)), magneto-optical media (e.g., a floptical disk), a hardwaredevice (e.g., a Read Only Memory (ROM), a Random Access Memory (RAM), aflash memory), and the like. In addition, the program instructions mayinclude high class language codes, which can be executed in a computerby using an interpreter, as well as machine codes made by a compiler.The aforementioned hardware device may be configured to operate as oneor more software modules in order to perform the operation of thepresent disclosure, and vice versa.

FIG. 14 is a cross-sectional view schematically illustrating theconfiguration of an electronic device 1400 according to one of variousembodiments of the present disclosure in a folded state. FIG. 15 is across-sectional view schematically illustrating the configuration of anelectronic device 1500 according to another one of various embodimentsof the present disclosure in a folded state.

According to various embodiments of the present disclosure, theelectronic device 1400 or 1500 may be folded such that the displaydevice (e.g., the display element 1402) can be exposed to the outside,as illustrated in FIG. 14. Likewise, the electronic device 1400 or 1500may be folded such that the display device (e.g., display element 1502)can be concealed, as illustrated in FIG. 15. For example, according toan embodiment, the window member 1403 or 1503 may be located on theouter or inner face of the electronic device 1400 or 1500 in the statein which the electronic device 1400 or 1500 is folded. For example, asillustrated in FIG. 14, when the electronic device 1400 is folded, thewindow member 1403 is positioned on the outer face of the electronicdevice 1400 such that the screen output region of the display device1402 can be exposed. In another embodiment, as illustrated in FIG. 15,when the electronic device 1500 is folded, the window member 1503 may bepositioned on the inner face of the electronic device 1500 such that thedisplay element 1502 can be concealed.

The display element 1402 or 1502 of the electronic device 1400 or 1500can be protected by the cover panel 1401 or 1501 and the window member1403 or 1503. For example, the cover panel 1401 or 1501 may be disposedto cover the display element 1402 or 1502 on one face of the displayelement 1402 or 1502, and the window member 1403 or 1503 may be coupledto face the other face of the display device 1402 or 1502.

According to various embodiments of the present disclosure, theabove-mentioned curved portion or stepped portion does not necessarilyhave to be formed as long as the window member is flexibly deformedcorresponding to the folding operation of the electronic device and theflat shape (or state) or the curved shape (or state) can be stablymaintained even if external pressure (e.g., the user's touch input) isapplied. For example, according to various embodiments of the presentdisclosure, the window member may be fabricated in a flat shape or afilm shape having a substantially uniform thickness. For example, aswill be described with reference to FIGS. 16 to 20, the first filmmember may be laminated on the window member, making the window memberthinner so as to stably maintain the flat shape or the curved shapethereof while securing flexibility.

FIGS. 16 to 20 are cross-sectional views illustrating partialconfigurations of display devices according to various embodiments ofthe present disclosure, respectively.

Referring to FIG. 16, according to various embodiments of the presentdisclosure, a display device 1605 (e.g., the display device 15 of FIG.4) may further include a first film member 1655 laminated on a windowmember 1653. The window member 1653 may include, for example, a thinglass, and may have a flat shape or a film shape with a substantiallyuniform thickness in the entire region thereof. According to oneembodiment, the window member 1653 may be made entirely or partly oftempered glass by a chemical strengthening treatment.

According to various embodiments, the first film member 1655 may belaminated on at least one face of the window member 1653. For example,the first film member 1655 may be laminated on the outer face of thewindow member 1653, which is exposed to the outside, thereby protectingthe window member 1653 from the external environment. According tovarious embodiments, the first film member 1655 may include a polyimidefilm or a thermoplastic polyurethane film, and in some embodiments, thefirst film member 1655 may include a hard coating component or ananti-fingerprint coating component. For example, the first film member1655 may protect the window member 1653 from damage, such as scratches,or contamination, such as stains or foreign matter adhered thereto.

Referring to FIG. 17, according to various embodiments of the presentdisclosure, a display device 1705 may further include a first filmmember 1755 laminated to a window member 1753 and a second film member1757 bonded to the surface of the first film member 1755. The secondfilm member 1757 may protect the window member 1753 together with thefirst film member 1755, and may be formed of a polyimide film or athermoplastic polyurethane film. In some embodiments, the second filmmember 1757 may prevent the window member 1753 and/or the first filmmember 1755 from being damaged or contaminated.

Referring to FIG. 18, according to various embodiments of the presentdisclosure, a display device 1805 may include first film members 1855,which are respectively laminated on both faces of a window member 1853.For example, according to various embodiments of the present disclosure,the first film member 1855 described above may be laminated on any oneface of the window member 1853, or may be laminated on each face of thewindow member 1853. Although not illustrated, the second film member(e.g., the second film member 1757 of FIG. 17) described above may befurther attached to the surface of any one of the first film members1855.

Referring to FIG. 19, according to various embodiments of the presentdisclosure, a display device 1905 may include a reinforcing layer 1959forming a layer, which is the same as a window member 1953. Thereinforcing layer 1959 may be disposed such that an area of the windowmember 1953, which is deformed in a curved shape, may be partiallyreplaced with the reinforcing layer 1959 when the above-describedelectronic device (e.g., the electronic device 1400 or 1500 illustratedin FIG. 14 or FIG. 15) is folded. The reinforcing layer 1959 may improvethe flexibility in, for example, a region of the layer in which thewindow member 1953 is disposed. In some embodiments, the reinforcinglayer 1959 is able to compensate for a difference in image qualitybetween a portion of the region, in which the window member 1953 is notdisposed and a region in which the window member 1953 is disposed. Thedisplay device 1905 may further include a first film member 1955laminated on one face of the window member 1953 and/or one face of thereinforcing layer 1959. The first film member 1955 is able to preventthe window member 1953 and/or the reinforcing layer 1959 from beingdamaged or contaminated. Although not illustrated, the above-describedsecond film member (e.g., the second film member 1757 of FIG. 17) may befurther attached to the surface of the first film member 1955.

Referring to FIG. 20, according to various embodiments of the presentdisclosure, a display device 2005 may include a curved portion and/or astepped portion (e.g., the curved portion 159 a of FIG. 4) formed on oneface (or each face) of a window member 2053, and a curved portion, whichis formed on one face of the window member 2053, may be filled with atransparent synthetic resin, an optical adhesive, or the like, therebyforming a reinforcing layer 2059. According to various embodiments, thedisplay device 2005 may further include a first film member 2055, whichis laminated on one face of the window member 2053, which is formed withthe reinforcing layer 2059, and/or the other face of the window member2053. The first film member 2055 is able to prevent the window member2053 and/or the reinforcing layer 2059 from being damaged orcontaminated. Although not illustrated, the above-described second filmmember (e.g., the second film member 1757 of FIG. 17) may be furtherattached to the surface of the first film member 2055.

As described above, according to various embodiments of the presentdisclosure, a display device may include: a display element, at least aportion of which is deformable in a curved shape; and a flexible windowmember stacked on the display element. A portion of the window membermay be formed to have a thickness smaller than the thickness of aremaining portion of the window member.

According to various embodiments, the display device may further includea reinforcing layer stacked on one face of the window member. Thereinforcing layer may compensate for a variation in the quality of animage transmitted through the window member, the variation being causedby the difference in the thickness of the window member.

According to various embodiments, in at least one face of the windowmember, a portion of the window member may include a stepped portion ora curved portion such that the portion of the window member has athickness smaller than the thickness of a remaining portion of thewindow member.

According to various embodiments, the stepped portion may have a grooveshape that extends in the width direction of the window member.

According to various embodiments, the stepped portion may have a stepshape, which gradually increases the thickness of the window member froma center thereof toward an edge thereof in the longitudinal direction ofthe window member.

According to various embodiments, the stepped portion may include acentral flat portion and an inclined portion extending toward the edgein the longitudinal direction of the window member.

According to various embodiments, the stepped portion may have a grooveshape, which extends in the width direction of the window member andgradually increases the thickness of the window member from the centertoward the edge in the longitudinal direction of the window member.

According to various embodiments, the stepped portion or the curvedportion may be formed on each face of the window member.

According to various embodiments, the stepped portion or the curvedportion may be formed on a face, which becomes convex when the windowmember is deformed in a curved shape.

According to various embodiments, the above-described display device mayfurther include a reinforcing layer formed in at least the steppedportion or the curved portion on the window member. The reinforcinglayer may compensate for a variation in the quality of image transmittedthrough the window member, the variation being caused by a difference inthe thickness of the window member.

According to various embodiments, the reinforcing layer may be formed inan entirety of at least one face of the window member, in which thestepped portion or the curved portion is formed.

According to various embodiments of the present disclosure, a displaydevice may include:

a display element, at least a portion of which is deformable in a curvedshape;

a flexible window member stacked on the display element; and

a first film member laminated on at least one face of the window member.

According to various embodiments, the first film member may include apolyimide film or a thermoplastic polyurethane film.

According to various embodiments, the first film member may contain acured coating component or an anti-fingerprint coating component.

According to various embodiments, the display device may further includea second film member bonded to a surface of the first member.

According to various embodiments, a portion of the window member may beformed to have a thickness smaller than the thickness of a remainingportion of the window member.

An electronic device according to various embodiments of the presentdisclosure may include the display device described above.

According to various embodiments, the electronic device may furtherinclude: a first housing; a second housing that pivots in a direction ofbeing folded or unfolded with respect to the first housing; and a hingedevice, which pivotably couples the second housing to the first housing.A portion of the display device may be mounted on the first housing anda remaining portion of the display device may be mounted on the secondhousing so as to be folded or unfolded with respect to the secondhousing.

According to various embodiments, the display device may be formed suchthat a portion of the display device adjacent to the hinge device has athickness smaller than the thickness of a remaining portion of thedisplay device.

According to various embodiments, the display device may be deformedinto a curved shape in a portion adjacent to the hinge device when thesecond housing is folded to the first housing.

While the present disclosure has been shown and described with referenceto certain embodiments thereof, it will be understood by those skilledin the art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the present disclosure asdefined by the appended claims.

The invention claimed is:
 1. A display device capable offolding/unfolding according to a user operation, the display devicecomprising: a display panel configured to be folded at a folding areaaccording to the user operation; and a flexible window member comprisingglass and stacked on the display panel, wherein the window memberincludes a trapezoid stepped portion, formed on a rear face of thewindow member, corresponding to the folding area such that the windowmember has a first thickness in the trapezoid stepped portion and asecond thickness greater than the first thickness in portions of thewindow member other than in the trapezoid stepped portion, wherein thetrapezoid stepped portion formed on the rear face of the window memberis fully filled with a transparent synthetic resin or an opticaladhesive to provide mechanical strength and compensation for deviationin optical quality that may occur due to variation in thickness of thewindow member.
 2. The display device of claim 1, wherein the trapezoidstepped portion formed on the rear face of the window member isconfigured to become convex when the window member is folded.
 3. Thedisplay device of claim 1, wherein the transparent synthetic resin orthe optical adhesive is further formed on an entirety of the rear faceof the window member.
 4. The display device of claim 3, furthercomprising: a first film member laminated on a front face of the windowmember, the first film member comprising a polyimide film or athermoplastic polyurethane film, and the first film member including ahard coating layer or an anti-fingerprint coating layer.
 5. The displaydevice of claim 1, further comprising: a first film member laminated ona front face of the window member, the first film member including apolyimide film or a thermoplastic polyurethane film, and the first filmmember including a hard coating layer or an anti-fingerprint coatinglayer.
 6. The display device of claim 4, further comprising a secondfilm member bonded to a surface of the first film member.
 7. Anelectronic device capable of folding/unfolding according to a useroperation, the electronic device comprising: a first housing; a secondhousing that pivots in a direction of being folded or unfolded withrespect to the first housing; a hinge device, which pivotably couplesthe second housing to the first housing; a display panel configured tobe folded at a folding area according to the user operation, a portionof the display panel being mounted on the first housing and anotherportion of the display panel being mounted on the second housing so asto be folded or unfolded according to the user operation; and a flexiblewindow member comprising glass and stacked on the display panel, whereinthe window member includes a trapezoid stepped portion, formed on a rearface of the window member, corresponding to the folding area such thatthe window member has a first thickness in the trapezoid stepped portionand second thickness greater than the first thickness in an area otherthan the trapezoid stepped portion, wherein the trapezoid steppedportion formed on the rear face of the window member is fully filledwith a transparent synthetic resin or an optical adhesive to providemechanical strength and compensation for deviation in optical qualitythat may occur due to variation in thickness of the window member. 8.The electronic device of claim 7, wherein the trapezoid stepped portionof the window member is disposed adjacent to the hinge device.
 9. Theelectronic device of claim 7, wherein the display panel is deformed intoa curved shape in a portion adjacent to the hinge device when the secondhousing is folded to the first housing.
 10. The electronic device ofclaim 7, wherein the trapezoid stepped portion is formed on both facesof the window member and are symmetrically arranged with respect to eachother.
 11. The electronic device of claim 7, wherein the transparentsynthetic resin or the optical adhesive is further formed on an entiretyof the rear face of the window member.
 12. The electronic device ofclaim 7, further comprising: a first film member laminated on a frontface of the window member, the first film member comprising a polyimidefilm or a thermoplastic polyurethane film, and the first film memberincluding a hard coating layer or an anti-fingerprint coating layer. 13.The electronic device of claim 7, wherein the trapezoid stepped portionformed on the rear face of the window member is configured to becomeconvex when the window member is folded.
 14. The electronic device ofclaim 7, further comprising a second film member bonded to a surface ofthe first film member.